Problem: Stephanie ate 1 slice of pie. Luis ate 1 slice. If there were 1 slice remaining, what fraction of the pie was eaten?
Answer: $\text{fraction of pie eaten} = \dfrac{\text{number of slices eaten}}{\text{number of slices total}}$ Since they ate 2 slices of pie with 1 slice remaining, they must have begun with 3 slices. They ate ${2}$ out of $3$ slices. They ate $\dfrac{2}{3}$ of the pie.